Zoo Atlanta gorilla takes own blood pressure

Vet Hayley Murphy explains why

Consider this a new twist on the phrase “a trained monkey could do that.”

In this case, actually, it’s a trained gorilla. Ozzie, the oldest of Zoo Atlanta’s 22 gorillas, has learned to take his blood pressure. It seems that heart disease is the main killer of gorillas in captivity. So Zoo Atlanta entered into a partnership with the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University to come up with a way to get blood pressure readings from the animals while they are awake.

Biomedical engineering students at Georgia Tech developed the “Gorilla Tough Cuff,” and Zoo Atlanta became the first place in the world to do the awake readings. More time is needed before veterinarians establish the normal blood pressure range for adult male gorillas.

Dr. Hayley Murphy, director of veterinary services at the zoo, talks about stress, Lipitor and pudding.

Q: Why measure a gorilla’s blood pressure?

A: Gorillas have heart disease in captivity. So we started asking [zoos] if they could get blood pressures on awake gorillas because we suspected some of the heart disease was due to high blood pressure. But because gorillas are not that easy to work with, nobody had ever gotten a blood pressure on an awake gorilla. We had data from anesthetized gorillas.

Q: But an anesthetized gorilla, what’s that going to give you? Their heart rate would slow because they are relaxed, right?

A: Right. What we didn’t know was how much the drugs were affecting the actual blood pressure readings.

Q: So where does Georgia Tech come in?

A: They had students that needed an interesting project, and they were always approaching the zoo for ideas. We had a really great project that needed to be done. So the two clicked. Gorillas are wild animals, so we really need equipment that would stand up to a gorilla pulling on it.

Q: What’s the difference then in the stress level between a gorilla in the wild and one in captivity?

A: Everybody has stress to live with. [Laughs] There are a lot of unknowns with the heart disease. We don’t know exactly what’s causing it. Is it nutritional? Is it stress? Is it genetic? Is it contagious? Is it infectious? The kind of disease they get could be based on high blood pressure.

Q: How did you train them?

A: It takes a lot of patience. When the animal does something you want it to do, it gets positive reinforcement and a treat. So every time Ozzie would put his hand in the blood pressure cuff that the Georgia Tech students developed, he got a treat. And eventually we started blowing up the cuff, a very little bit at a time and then released it to let him know that wasn’t so bad. So, over time, you build their trust and reinforce the fact that nothing bad is happening here, and [he] gets a treat. Now he’s used to doing it.

Q: What kind of treat did Ozzie get?

A: He likes pudding, sugar-free pudding.

Q: How does this thing work? How long does it take to get a reading? About as long as it would take to get a human’s pressure reading?

A: This Gorilla Tough Cuff, he puts his arm in there and that’s protected in a cage so that there’s no risk to the keepers. And [the cuff] is hooked up to a machine that pumps it up. We do three to four readings at a session and each session takes about 90 seconds.

Q: How long have you been using this?

A: We got the prototype in March and our first readings on July 4.

Q: So just Ozzie is doing this now?

A: We have four other males in active training right now. We started with Ozzie because he’s our oldest male and at the greatest risk for cardiac problems. Heart disease is mainly a male-based disease in gorillas.

Q: Is this reliable?

A: Once we get more readings, I think it will prove to be reliable. His readings have been fairly consistent. But until we get more readings from other animals, I don’t think we can say much yet. But just to get a gorilla willing to do it when he’s awake is pretty amazing. Nobody thought it could be done. Everybody thought the minute you start squeezing their arm, they’re going to pull out and destroy the machine.

Q: But really, what’s the goal of all of this? To keep the ones in captivity healthy longer?

A: To improve the health of the captive animals. If we have an animal with heart disease, and we can start them on treatment and be able to monitor their response to the treatment without anesthesia, that’s a huge advantage for the animal and for us.

Q: By treatment, you mean like putting them on Lipitor or something?

A: Some zoos are using Lipitor, but we don’t have direct evidence that cholesterol is a problem. I consult on gorillas all around the country, and we do have gorillas with diagnosed heart disease on treatments — beta blockers and ACE inhibitors, the same thing humans would use.

Q: You’ve demonstrated this to other zookeepers and what’s been the response?

A: The phone is ringing off the hook. People really want to get this device.

Q: How much does this machine cost, and who’s going to get the licensing rights?

A: That’s going to be Georgia Tech. I don’t know what the cost is, but it’s under patent through Georgia Tech. Hopefully, it’s going to be available soon to a wide range of zoos.

Q: Do you really think this can prolong the lives of the animals?

A: In and of itself, no, but it can aid in our diagnostic capabilities.

Q: So back to the pudding. What’s Ozzie’s favorite, chocolate or vanilla?

A: I think he usually gets vanilla.